Conventional pulsed power energy storage systems use air or oil-cooled transformers for high voltage step-up. These are limited in power density due to either low cooling efficiency or low dielectric density.
Prior technologies include fluoro-carbon fluids such as FC-72 and FC-77 for transformer cooling with two-phase vapor/liquid, such as for 60 Hz steady-state transformers with vapor cooling. Some refrigerants will evaporate in a sealed chamber until the vapor pressure in the system is at a pressure corresponding to its environmental temperature. These fluids are not suitable for pulsed power megawatt level systems, including those operating at frequencies such as 20,000 Hz.
Advances in hydro-fluoro-ether (HFE) chemistry now permit HFE fluids to be used profitably for insulating and cooling high voltage mega-watt rated power transformers, such as for radar pulsed power or electromagnetic pulsed power. The combination of an HFE insulated/cooled transformer with an inertial energy storage device produces a regenerative system with power/energy densities required by government programs, and allows a safe and efficient interface with high density lithium battery energy storage systems.
Pulsed power at the megawatt level requires new topologies for the magnetics of the transformer and the electrical machinery, as well as enhanced cooling to reduce component critical temperatures, extend lifetime and allow faster repetition rates for an effector. A new excitation scheme for the inertial storage module results in a significantly faster rate-of-rise of output voltage and power.